The present invention relates to a seal for the frame of an aperture of the body of an automobile or similar. A process for production of this seal is also a subject of the invention.
It is known that such seals for automobile door or trunk frames generally comprise a grip-forming channel section of U-shaped cross-section, in a thermoplastic material provided with a metal reinforcement, this channel section being intended to cap a projecting part of the frame so as to secure the seal to it, and a resiliently deformable tubular element, generally in a cellular material, which is contiguous to the grip-forming channel section and which is intended to be compressed between the frame and the corresponding movable element of the automobile so as to ensure tightness.
The grip-forming channel section and the tubular element may be coextruded from the same extrusion head. They may also be produced separately and be secured to one another afterwards by bonding.
It is to the latter production process that the present invention relates and it aims to remedy the disadvantages encountered when fitting these seals onto body opening frames which have very sharp curves in some corners.
In fact, in such locations, the tubular element, which is of a relatively large volume and whereof the cross-section generally has a complex profile, tends, on the one hand, to form wrinkles all the more pronounced as the curvature of the frame becomes sharper, on the other hand, to become offset with respect to the grip-forming channel section and to become deformed.
This disadvantage is well-known in the Art (see the Applicant's French patents and patent applications No 2,247,341, 2,133,107, 2,469,321 and 2,624,191) and various solutions to this problem have been proposed, but they are all relatively complicated and costly, because in most instances they involve adding a local excess of material onto the part of the seal located in the corner of the frame.